Means for cementing wells



Dec. 11, 1928.

, A. H. HOBART MEANS FOR CEMENTING WELLS Filed Dec. 14, 1926 im a l l A9Patented Dec. 11, 1928.

UNITED STATES ARTHUR HAROLD HOBART, HONOLULU, TERRITORY OI MEANS FORonlvtnu rnve WELLS.

Application filed December 14, 1926. Serial No. 154,750.

This invention relates to means and method for introducing cementitiousmaterial into the shaft of artesian wells for the purpose'ofsealingthem.

The object of the invention 1s to provide means for conserving the watersupply. of artesianbasins by stopping the flow therefrom, throughabandoned wells.

In the drilling of deep wells to obtain water supply in certainlocalities, as example, in the Hawaiian Islands, the wells are projectedvto varyingrdepths from 250 to lQOO feet, in order to reach the artesianbasins which lie from 200 to 900 feet below sea level.

These wells, before reaching the fresh or sweet water bearing stratapass, throughsand, coral, or other pervious material, which 1s saturatedwith salt water from the ocean.

Inthe Work of projecting thesewells, metallic casings are inserted intothe well bore, and carried-to a point below this perv ous strata,-toshut off such salt-water as might find its way into the well through thepervious strata, from the ocean. These casings are left in, thecompleted well to continue to keep the salt water from entering andcommingling with the sweet Water-from the lower basin source.

The water emanating from the pervgious strata being salty, soon rustsout the metallic casing, causing either a leakage of salt water into thewell, or a leakage of sweet water outthrough the pervious strata, thusdepleting the basin, and lowering the head of flow from the well abovesea. level.

When a well so affected is abandoned on account of its not warrantingre-casing, or for other reasons, it is considered good practice .tocompletely seal it off, for the dual purposeof shutting out the 1ncomingsalt water from the sea, into the basin, and to stop further depletionof the basin supply by any outward flow through the pervious strata.

Inthe localities referred to, the head of the flow of artesian Wells hasdropped approximately fifty per cent in'the past fifty years,andpartially :due to the lowering of the head, there has occurred thecreeping in from the ocean salt Water into the seaward ends of many ofthe basins, making the water from wells tapping-such basins, too saltyto be of value for irrigation or other purposes. I have found that bysealing offfrom ten to two-hundredfeet in the bottom of some of thesewells, that I have reduced the salt content from 10% to 70%, and havecompletely stopped further depletion of the basinsco nprising the sourceof these wells.

Broadly speaking, the preferred embodiment of my invention comprises atubular container having a detachable bottom adapted to support a chargeOf cGlIlQIltltiOUS material positioned within said container, and meansfor detaching the bottom, ,to release the material from said container,when the container has reached a predetermined position within the well,and my invention furtherconsists in the formation of, and the depositingat. fixed positions withinthe well, cementitious material capableofresisting the upward flow of water from the source, of supply, whilethe cementitious material is in a plastic condition.

In the p-rocessof-sealingoif sub-surface water, and waterfrom thebottomandin'termediate zones in deep Wells, it is customary to introducecement into the well by means of an elongated container, .1sually calleda dump .bailer, having a ,-foot ,valv,e which is opened when the bailercomes in contact with the bottom of the. well, supposedly dischargingthe cement at this point.

, Where the bailer encounters softmaterial in'the bottom off-he well,the dart of the bailer valve willsink in,.and fail to function, and thebailer fails of discharge. Furthermore, the foot valves in common useare so constructedtha-t even when opened, they constrict the dischargeorifice of the bailer to such an extent that the cementitious materialpositionedavithin the bail-er often fails to be exuded. This non-actionof the bailer cannot be ascertained until the ba-iler is withdrawnfromthe well, preparatory to again loading for another charge.

I overcome ,t,l,1ese:.difiiculties by my improved bailer, in providingat thebottom thereof, an unrestricted discharge opening, and meansformechanically evacuating the cementitious.,material within the bailer.

It has also'been found that in the operation of depositing cement-indeep wells, especially where the head or volume of flow of the watertherefrom, is of considerablemagnitude, that the ordinary cementitiousmaterial having about the specific gravity of Portland cement, would notresist this flow, but'vvould be buoyed up and carried out of the wellwith the Water. I overcome this difficulty increasing the specificgravity of the cementitiousmaterial I use, by cominingling .therewithpieces of; iron, such as chips, borings, boiler 'punchings, etc., aswell as scrap lead and other heavy metals.

I maymake my first-deposits of cementitious compound, rich in ironingredients, and I may add other ingredients which will materiallyhasten the oxidation of the iron ingredients from the effects of saltwater thereon, into a solid mass with the casing, making a permanentimmovable plug, thereby reduc ing the flow of water, which willfacilitate the maintenance in positionwhile setting, the.

known in the art, until the intermediate point is reached at which thewater seal is to be placed.

I accomplish the effective sealing of deep wells by a method andapparatus herein described and'illustrated in the accompanying drawingsforming a part of these specifications.

In the drawings:

Fig.1 is a side elevation and partial section of my improved dump bailercharged with cementitious material ready for use in a well. I

Fig. 2 is a similar view to Fig. 1, showing the position assumed by thecomponent parts of the bailer upon reaching the bottom of the well.

Fig. 3 is a side elevation with parts broken away, of the bailer afterthe charge of cementit-ious material has been evacuated.

Fig.4 is a side elevation of pre-cast concrete cylinders positioned inthe bottom of the well upon which is to be deposited cementitiousmaterial.

Fig. 5 is. an enlarged detailed view of the latch mechanism.

Fig. 6 is a view taken on the line 6-6 shown in Fig. 5.

V In the drawings, 1 indicates the tubular container for holding thecementitious material, 2 is the closure member for the tubular from, arethe companion supporting bars 5' and 5. Positioned on each side of thesupporting bars 5 and 5, at their upper ends are transverse companionbars 6 and 6 (6' not shown) A similar pair of transverse companion bars7 and 7 (7 not shown) are positioned on the supporting bars 5 and 5 ashort distance below the bars 6 and 6'.

Intermediate of the bars 6 and 6 and bars 7 and 7, there is formed arectangular aperture within which is positioned the slidable "member 10,formed rectangular in cross section to conform to the aperture in whichit slides. The slidable bar 10 is adapted for vertical movement withrespect to the con tainer 1, but is heldagainst a rotative movementtherein.

The slidable'mc'mber 10 has formed in itsl upper end the eye 11, and inits lower end the eye 12. Located near the upper end of the slidablemember 10, is a spring actuated pawl 8 positioned within the recess 18formed in the body of the member 10. The pawl 8 pivoted on the rivet 19,is adapted to be held in extended position by the compression spring 20.To guard against the pawl 8, or the spr1ng20 becoming inoperative bychain 13 is shackled to the eye bolt 14': projecting from the upper endof the closure member '2.

The closure member 2 comprises the valve seat 3, and the tubularextension 9, which is filled with lead or other heavy material toprovide a suitable anchor for the purposes hereinafter described.

The upper terminal of the slidable member 10 is adapted to be connectedby the eye 11, to the lowering means (not shown) by which the apparatusis lowered into the well, and usually comprises a portion of the stringof well tools applied in a manner well known in the art. y e

To those skilled in the art, it will be obvious that as the containerand its component parts, are suspended by the eye 11, of the member 10,a strain will be applied tothe chain 13 which will hold the bottommember 2, in position to form a closure with the rim l of the container1, forming an effective seal therewith. With the containerl, thus suspended, it is adapted to hold a charge of cementitious material placedtherein, and to retain it during the operation of lowering the apparatusto the point in the well desired. When this point has been reached,either at the natural bottom of the well, or at an artificial bottombuilt up by the use of precast concrete cylinders as shown in Fig. Q,the lower closure member 2, coming in mm tact therewith, arrests thedownward movement of the container 1. ,Such contact however, does notabruptly arrest the downward movement of the slidable member 10 which isfree to continue its downward movement, actuated by the pressurethereon, of the well tools being lowered, until the eye 11 has reached aposition contiguous with the companion transverse bars 6 and 6. lVhenthis position has been reached by the sliding member 10, there will haveoccurred a slackening of the links of the chain 13, with a depositingof-such slack links on top of the cementitious material as shown in Fig.2. and the pawl 8, will have reached a position below the transversebars 6 and 6 and assumed an extended position to engage the transversebars 6 and 6 in its subsequent upward movement.

The apparatus is now in a position for discharging the cementitiousmaterial within the container. This discharge is accomplished by theupward movement of the well tools which carry with them the slidablemember 10. In the upward movement of the member 10, the pawl 8 beingextended, en-

gages the transverse bar 6, and through such engagement, the container 1is lifted and carried upward with the movement of the bar member 10,thereby severing the closure between the annular rim 4 of the container1 and the valve seat 3 of the closure member 2, separating the container1 from the closure member 2, to the extent of the slack previouslyformed in the chain 13, thereby allowing a free discharge of thecementitious material from the container 1.

To facilitate the discharge and to assure a complete functioningthereof, a reciprocal movement is given to the hoisting means which inturn causes the chain 13, secured at its lower end to the closure member2 acting as an anchor, to be reciprocated through any cementitiousmaterial in its path, and to accelerate an evacuation thereof from thecontainer 1.

As further assurances of a complete cleaning out of the interior of thecontainer 1, the apparatus is lifted to a zone above the cementitiousdeposit, and again given a reciprocating movement, forcing the waterstanding in the well, through which the container is reciprocated to acton the sides thereof to remove any particles adhering thereto.

The apparatus is then hoisted to the surface of the ground and theprocess is repeated until a sufiicient amount of cementitious materialhas been deposited within the well to insure a complete sealing thereof.

With the foregoing description I have referred to a method and apparatusforcementing wells, and while I have described the preferred embodimentof my invention, I desire it to be understood that I do not limit myselfto the specific details shown, as other methods and means may beemployed to carry out my invention, Withoutdeparting from the spiritthereof.

WVhat I do claim and desire to secure by Letters Patent is:

In a device for cementing wells, comprising a supporting rod, a.cylindrical anchor member suspended from said rod by loose jointedconnections and adapted to be positioned on the bottom of the well, atubular member surrounding said rod adapted to contain cementitiousmaterial and supported on said anchor member, a bail member at tached tosaid tubular member recessed to engage the rod therein, a latch pawlpivoted in said rod adapted to pass the bail member on a downwardmovement of the rod and to engage'the bail member in its upward movementwhereby the tubular member is lifted and spaced apart from the anchormember in the withdrawal movement of the apparatus from the well.

In testimony whereof I have affixed my signature.

ARTHUR HAROLD HOBART.

